Soil-borne plant pathogenic fungi cause severe economic losses in the agricultural and horticultural industries. For example, root and crown rot diseases caused by soil-borne fungal pathogens such as Pythium spp. are a widespread and recurrent problem in plant production. As another example, Rhizoctonia solani is a major soil-borne fungal phytopathogen, and is associated with diseases such as damping-off, root rot, and leaf and stem rot in many plant species, including greenhouse crops. R. solani is also associated with brown patch in creeping bentgrass and various other turfgrasses of high commercial value. Species of Alternaria and Fusarium are associated with diseases such as early blight of tomato and Fusarium wilt of numerous fruit and vegetable crops.
In light of actual and potential environmental and health hazards associated with pesticide use, fungicide use may be restricted. As a result, growers have sought alternative approaches to disease control. These alternative approaches include the use of biological agents and disease-suppressive growing media. The use of biologically active agents in the control of plant pests and diseases has become especially important. Despite the recent commercialization of several types of microbial biocontrol agents, questions still remain about the ability of these agents to provide consistent and reliable control against fungal pathogens and insect pests.
The use of biologically active agents in the cleanup of toxic waste sites has become especially important. Despite attempts to identify microbial environmental control agents, questions still remain about the ability of these agents to provide consistent and reliable cleanup of toxic waste sites. Factors militating against the propagation and survival of microorganisms introduced into polluted soils include: competition with other organisms for nutrients, water and space; parasitism, antibiosis and predation by other organisms; and unfavorable physicochemical parameters of the soil milieu, including sub-optimal pH, water and oxygen concentrations. In the case of polluted soils, problems associated with survival and propagation of microorganisms introduced into such soil may be exacerbated by the presence of toxic pollutants at concentrations that are inimical to microbial growth. There has long been a need for microorganisms that have suitable bioremediation properties, e.g., bacteria that consume, over a period of time, accumulated hydrocarbons.
Current bioremediation methodology in the main employs the addition of nutrients to treatment sites to enhance the activity of in situ populations or by the treatment of above ground waste and solid sludges by methods including land farming, composting or slurry reactors. Absent, by and large, has been the practicability of applying organisms exogenously since these are rapidly eliminated by environmental constraints and existing populations. There is a strong interest in applying bioremediation approaches to remove toxic compounds from the environment.
Fungal infections can result in life-threatening infections in individuals, especially immunocompromised patients, such as persons suffering from AIDS or cancer. For example, Mucor infections present serious consequences to immunocompromised patients and to diabetics. Mucor infections often result in infection of the paranasal sinuses, with extension into the brain (rhinocerebral). Orbital infection may spread to involve the eye as well. Other complications include spread to the lung, skin and gastrointestinal tract. As another example, Aspergillus infections present primarily as pulmonary complications in immunocompromised patients, often resulting in a necrotizing pneumonia. There can be widespread dissemination to other organs.
Though various treatments are available, including, among others, nystatin, amphotericin B, haloprogin and sulfa derivatives, toxic affects are not uncommon; thus amphotericin B is toxic to the kidneys and treatment of mucocutaneous candidiasis with antibiotics alone has not met with success. Similar equivocal results are experienced with other treatments as well. The potential for a new treatment from a bacterium with demonstrated activity against a wide range of fungi may therefore be of significant therapeutic value.